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Abstract:

A sheet manufacturing apparatus includes a rotatable drum unit that
includes an opening unit having a plurality of openings on a surface
thereof and a cylindrical unit having no opening; a material supply unit
that is provided to supply a material containing fibers to the drum unit
by airflow; and a forming unit that forms a sheet by using the material
passing through the openings, in which at least one of the drum unit and
the material supply unit has a dispersion unit in which airflow is
dispersed further on a downstream side than on an upstream side in a
supply direction of the airflow.

Claims:

1. A sheet manufacturing apparatus comprising: a rotatable drum unit that
includes an opening section having a plurality of openings on a surface
thereof and a cylindrical section having no opening; a material supply
unit that is provided to supply a material containing fibers to the drum
unit by airflow; and a forming unit that forms a sheet by using the
material passing through the openings, wherein at least one of the drum
unit and the material supply unit has a diffusion section in which
airflow is diffused further on a downstream side than on an upstream side
in a supply direction of the airflow.

2. The sheet manufacturing apparatus according to claim 1, wherein the
diffusion section is an enlarged part of which a cross-sectional area on
the downstream side is greater than a cross-sectional area on the
upstream side of the material supply unit.

3. The sheet manufacturing apparatus according to claim 1, wherein the
diffusion section is a changing section that changes a direction of the
airflow within the drum unit.

4. The sheet manufacturing apparatus according to claim 1, wherein a
supply port of the material supply unit is positioned in a position in
which the airflow is diffused with respect to the opening section within
the drum unit.

5. The sheet manufacturing apparatus according to claim 1, further
comprising: a housing unit that surrounds a periphery of the drum unit;
and a suction unit that sucks air within the housing unit below the drum
unit, wherein outside air is suctioned from a sliding contact part
between the drum unit and the housing unit during suction by the suction
unit.

6. A sheet manufacturing apparatus comprising: a housing unit that
surrounds a periphery of a drum unit; and a suction unit that sucks air
within the housing unit below the drum unit, wherein outside air is
suctioned from a sliding contact part between the drum unit and the
housing unit during suction by the suction unit.

7. A sheet manufacturing apparatus comprising: a rotatable drum unit that
is a hollow cylindrical drum unit and includes an opening section having
a plurality of openings; a supply unit that includes a supply port for
supplying a material containing fibers transported by airflow to the drum
unit; and a forming unit that forms a sheet by using the material passing
through the openings of the drum unit, wherein the supply port is
disposed at a predetermined distance with respect to the opening section
of the drum unit in a rotation axis direction of the drum unit, and
wherein a diameter of the supply port is smaller than an internal
diameter of the drum unit.

Description:

BACKGROUND

[0001] 1. Technical Field

[0002] The present invention relates to a sheet manufacturing apparatus.

[0003] 2. Related Art

[0004] In the related art, a paper recycling apparatus including a paper
forming machine has been known. The paper forming machine has a forming
drum in which a small-hole screen is provided and a rotatable needle roll
that is provided within the forming drum, and is configured to disperse
fibers introduced into the forming drum into the atmosphere (for example,
see JP-A-2012-144819).

[0005] However, if airflow for introducing the fibers is not sufficiently
diffused within the forming drum, there is a problem that variation of an
airflow speed is increased within the forming drum, the fibers are caught
by the small-hole screen, and portions that cannot discharge the fibers
from the forming drum are generated. Furthermore, there is a problem that
the fibers are easily caught in an outer periphery portion of the drum in
the portions that cannot discharge the fibers, the caught fibers are
accumulated or fall, and texture of a sheet is deteriorated.

SUMMARY

[0006] The invention can be realized in the following aspects or
application examples.

Application Example 1

[0007] According to this application example, there is provided a sheet
manufacturing apparatus including a rotatable drum unit that includes an
opening section having a plurality of openings on a surface thereof and a
tubular unit having no opening; a material supply unit that is provided
to supply a material containing fibers to the drum unit by airflow; and a
forming unit that forms a sheet by using the material passing through the
openings. At least one of the drum unit and the material supply unit has
a diffusion section in which airflow is diffused further on a downstream
side than on an upstream side in a supply direction of the airflow.

[0008] In this case, the diffusion section is provided in the drum unit or
the material supply unit and the introduced airflow is diffused to a
peripheral surface of the drum unit by the diffusion section. Then, the
material is also efficiently dispersed according to the diffused airflow
in the drum unit or the material supply unit. Thus, it is possible to
reduce a portion through which the material does not pass in the drum
unit.

Application Example 2

[0009] In the sheet manufacturing apparatus according to the above
application example, the diffusion section may be an enlarged part of
which a cross-sectional area on the downstream side is greater than a
cross-sectional area on the upstream side of the material supply unit.

[0010] In this case, the airflow is introduced within the drum unit while
being diffused by increasing the cross-sectional area of the material
supply unit on the downstream side. Thus, the material is efficiently
dispersed in the drum unit and it is possible to reduce a portion through
which the material does not pass.

Application Example 3

[0011] In the sheet manufacturing apparatus according to the above
application example, the diffusion section may be a changing section that
changes a direction of the airflow within the drum unit.

[0012] In this case, a direction of the airflow introduced from the
material supply unit is changed by the changing section within the drum
unit. That is, the airflow is diffused within the drum unit. Thus, the
material is efficiently dispersed in the drum unit and it is possible to
reduce the portion through which the material does not pass.

Application Example 4

[0013] In the sheet manufacturing apparatus according to the above
application example, a supply port of the material supply unit may be
positioned in a position in which the airflow is diffused with respect to
the opening section within the drum unit.

[0014] In this case, the supply port of the material supply unit is
positioned in the position in which the airflow is diffused within the
drum unit. Thus, the airflow is introduced within the drum unit while
being diffused. Thus, the material is efficiently dispersed in the drum
unit and it is possible to reduce the portion through which the material
does not pass.

Application Example 5

[0015] The sheet manufacturing apparatus according to the above
application example may further include a housing unit that surrounds a
periphery of the drum unit; and a suction unit that sucks air within the
housing unit below the drum unit, in which outside air may be suctioned
from a sliding contact part between the drum unit and the housing unit
during suction by the suction unit.

[0016] In this case, the outside air is suctioned from the sliding contact
part between the drum unit and the housing unit in addition to the
diffusion of the airflow by the diffusion section. Thus, the airflow is
further diffused by the suctioned outside air within the drum unit. It is
possible to efficiently disperse the material within the drum unit.

Application Example 6

[0017] According to this application example, there is provided a sheet
manufacturing apparatus including a housing unit that surrounds a
periphery of a drum unit; and a suction unit that sucks air within the
housing unit below the drum unit. Outside air is suctioned from a sliding
contact part between the drum unit and the housing unit during suction by
the suction unit.

[0018] In this case, the outside air is suctioned from the sliding contact
part between the drum unit and the housing unit. Thus, lumps,
aggregation, and the like of the material within the drum unit or the
housing unit are reduced and texture of the sheet is improved.

[0019] In the sheet manufacturing apparatus according to Application
Examples 5 and 6, the sliding contact part between the drum unit and the
housing unit is a seal member for sealing a gap between the drum unit and
the housing unit. Furthermore, the outside air may be suctioned from the
gap without providing the seal member.

Application Example 7

[0020] According to this application example, there is provided a sheet
manufacturing apparatus including a rotatable drum unit that is a hollow
cylindrical drum unit and includes an opening section having a plurality
of openings; a supply unit that includes a supply port for supplying a
material containing fibers transported by airflow to the drum unit; and a
forming unit that forms a sheet by using the material passing through the
openings of the drum unit. The supply port is disposed at a predetermined
distance with respect to the opening section of the drum unit in a
rotation axis direction of the drum unit. A diameter of the supply port
is smaller than an internal diameter of the drum unit.

[0021] In this case, it is preferable that the supply port is disposed
such that, for example, a center of an inner diameter thereof is
positioned in the rotation axis direction of the drum unit.

Application Example 8

[0022] According to this application example, there is provided a sheet
manufacturing apparatus including a rotatable drum unit that includes an
opening section having a plurality of openings and a tubular section
having no opening; a supply unit that supplies a material containing
fibers to the drum unit; a transport path that communicates with the
supply unit and transports the material containing the fibers to the
supply unit by the airflow; and a forming unit that forms a sheet by
using the material passing through the openings of the drum unit. The
drum unit has a receiving port for receiving the material. The supply
unit has a supply port for supplying the material to the drum unit. The
supply port is disposed at a predetermined distance with respect to the
receiving port in a rotation axis direction of the drum unit. An area of
the supply port is smaller than an area of the receiving port.

[0023] A predetermined distance is provided between the supply port and
the receiving port, and the receiving port is greater than the supply
port in size. Thus, it is possible to diffuse the airflow transporting
the material from the supply port to the receiving port.

[0024] Here, the receiving port of the drum unit is, for example, a
boundary portion between the tubular section and the opening section.
More specifically, the receiving port is an inner circumference portion
of the drum unit drawing on a virtual plane perpendicular to a rotation
axis of the drum unit through the boundary between the tubular section
and the opening section. Furthermore, an area of the supply port and an
area of the receiving port are, for example, a cross-sectional area in a
direction perpendicular to the rotation axis of the drum unit.

Application Example 9

[0025] According to this application example, there is provided a sheet
manufacturing apparatus including a rotatable drum unit that includes an
opening section having a plurality of openings and a cylindrical section
having no opening; a supply unit for supplying a material containing
fibers to the drum unit; a transport path that communicates with the
supply unit and transports the material containing the fibers to the
supply unit by the airflow; a diffusion section that is provided at least
one of the drum unit and the supply unit, and diffuses airflow
transporting the material containing the fibers; and a forming unit that
forms a sheet by using the material passing through the openings of the
drum unit.

[0026] Here, when the diffusion section is provided in the supply unit,
for example, a portion of which a cross-sectional area (cross-sectional
area in a direction perpendicular to a flow direction of the airflow)
from the transport path side to the drum unit side in the supply unit
becomes large can be the diffusion section. Moreover, the entirety of the
supply unit may be the diffusion section.

[0027] Furthermore, when the diffusion section is provided in the drum
unit, for example, a plate member that is in the drum unit and is
disposed in a position facing the supply unit can be the diffusion
section. The plate member may be a flat plate, a curved shape, or a bent
shape, and a shape thereof is not limited when a shape of the plate
member can diffuse the airflow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention will be described with reference to the accompanying
drawings, wherein like numbers reference like elements.

[0029] FIG. 1 is a schematic view illustrating a configuration of a sheet
manufacturing apparatus according to a first embodiment.

[0030] FIG. 2A is a schematic view illustrating a configuration of an
accumulation unit according to the first embodiment and a sectional view
in a rotational axis direction.

[0031] FIG. 2B is a schematic view illustrating a configuration of the
accumulation unit according to the first embodiment and a sectional view
that is taken along line IIB-IIB in FIG. 2A.

[0032] FIG. 3 is a perspective view illustrating a configuration of a drum
according to the first embodiment.

[0033] FIG. 4 is a schematic view illustrating a configuration of an
accumulation unit according to a second embodiment.

[0034] FIG. 5 is a schematic view illustrating a configuration of an
accumulation unit according to a third embodiment.

[0035] FIG. 6 is a schematic view illustrating a configuration of an
accumulation unit according to a fourth embodiment.

[0036] FIG. 7A is a schematic view illustrating a configuration of an
accumulation unit according to Modification Example 1.

[0037] FIG. 7B is a schematic view illustrating a configuration of the
accumulation unit according to Modification Example 1.

[0038] FIG. 8 is a schematic view illustrating a configuration of an
accumulation unit according to Modification Example 2.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0039] Hereinafter, first to fourth embodiments of the invention will be
described with reference to the drawings. Moreover, in each view below,
scales of each member and the like are illustrated differently from real
scales to make each member and the like be recognizable sizes.

First Embodiment

[0040] First, a configuration of a sheet manufacturing apparatus will be
described. The sheet manufacturing apparatus is, for example, based on a
technique of forming a new sheet Pr from a raw material (material to be
defibrated) Pu such as pure pulp sheets and used paper. The sheet
manufacturing apparatus according to the embodiment includes a rotatable
drum that includes an opening section having a plurality of openings on a
surface thereof and a cylindrical section having no opening; a material
supply unit for supplying a material containing fibers to the drum by
airflow; and a forming unit that forms a sheet by using the material
passing through the openings. At least one of the drum and the material
supply unit has a diffusion section in which airflow is diffused further
on a downstream side than on an upstream side in a supply direction of
the airflow. Hereinafter, the detailed configuration of the sheet
manufacturing apparatus will be described.

[0041] FIG. 1 is a schematic view illustrating the configuration of the
sheet manufacturing apparatus according to the embodiment. As illustrated
in FIG. 1, a sheet manufacturing apparatus 1 of the embodiment includes a
supply unit 10, a crushing unit 20, a defibrating unit 30, a classifying
unit 40, a screening unit 50, an additive feeding unit 60, a blower 190,
an accumulation unit 70, a forming unit 100, and the like.

[0042] The supply unit 10 is provided for supplying a used paper Pu as the
raw material to the crushing unit 20. The supply unit 10 includes, for
example, a tray 11 in which a plurality of used papers Pu are overlapped
and stored, an automatic feeding mechanism 12 capable of continuously
feeding the used papers Pu in the tray 11 into the crushing unit 20, and
the like. The used paper Pu supplied to the sheet manufacturing apparatus
1 is, for example, paper of A4 size and the like mainly used in an
office.

[0043] The crushing unit 20 cuts supplied used paper Pu to paper pieces of
several centimeters square. The crushing unit 20 includes crushing blades
21 and configures a device for spreading cut widths of blades of a
conventional shredder. Thus, it is possible to easily cut the supplied
used paper Pu to the paper pieces. Then, cut paper pieces (crushed
papers) are supplied to the defibrating unit 30 through a pipe 201.

[0044] The defibrating unit 30 defibrates a material containing fibers in
the atmosphere. Specifically, the defibrating unit 30 includes rotating
rotary blades (not illustrated) and performs defibration to untangle the
crushed papers supplied from the crushing unit 20 in fibriform. In the
present application, what is defibrated by the defibrating unit 30 is
referred to as the material to be defibrated and what passes through the
defibrating unit 30 is referred to as the defibrated material. Moreover,
the defibrating unit 30 of the embodiment is a dry type and performs
defibration in the atmosphere. Coating materials (for example,
blur-preventing agent) to the paper such as ink and toner, and the like
to be printed are separated from the fiber by being particles
(hereinafter, referred to as "ink particles") of several tens of μm or
less by the defibrating process of the defibrating unit 30. Thus, the
defibrated material drawn out from the defibrating unit 30 is fiber and
the ink particles obtained by defibration of the paper pieces. Then, a
mechanism of generating airflow by rotation of the rotary blades is
provided and the defibrated fiber is transported to the classifying unit
40 in the atmosphere through a pipe 202 by riding on the airflow.
Moreover, an airflow generating device for generating the airflow to
transport the defibrated fiber to the classifying unit 40 through the
pipe 202 may be separately provided in the defibrating unit 30 when
required.

[0045] The classifying unit 40 classifies an introduced material that is
introduced by the airflow. In the embodiment, the defibrated material as
the introduced material is classified into the ink particles and the
fiber. The classifying unit 40 can classify the transported defibrated
material into the ink particles and the fiber by using the airflow, for
example, by applying a cyclone. Moreover, another airflow type classifier
may be used instead of the cyclone. In this case, as the airflow type
classifier other than the cyclone, for example, elbow jet, eddy
classifier, and the like are used. The airflow type classifier generates
a whirling airflow, separates, and classifies the defibrated material by
a difference in a centrifugal force received by a size and density of the
defibrated material. Thus, it is possible to adjust a classification
point by adjusting a speed of the airflow and the centrifugal force.
Thus, the defibrated material is separated into small ink particles of
relatively low density and the fiber of high density having particles
greater than the ink particles in size.

[0046] The classifying unit 40 of the embodiment is a tangent input type
cyclone and is configured of an inlet 40a through which the introduced
material is introduced from the defibrating unit 30, a cylindrical
section 41 to which the inlet 40a is attached in a tangent direction, a
conical unit 42 following a lower portion of the cylindrical section 41,
a lower outlet 40b provided in a lower portion of the conical unit 42,
and an upper air outlet 40c for discharging fine powder provided in an
upper center of the cylindrical section 41. A diameter of the conical
unit 42 is decreased going downward in a vertical direction.

[0047] In a classifying process, the airflow, on which the defibrated
material introduced from the inlet 40a of the classifying unit 40 rides,
is changed to a circumferential movement in the cylindrical section 41
and the conical unit 42, and the defibrated material is classified by
applying the centrifugal force. Then, the fiber that is greater than the
ink particles in size and has a high density moves to the lower outlet
40b and the ink particles that are relatively small and have a low
density are guided to the upper air outlet 40c as fine powder together
with air. Then, the ink particles are discharged from the upper air
outlet 40c of the classifying unit 40. Then, the discharged ink particles
are recovered in a receiving unit 80 through a pipe 206 connected to the
upper air outlet 40c of the classifying unit 40. On the other hand, a
classified material containing the classified fiber is transported from
the lower outlet 40b of the classifying unit 40 to the screening unit 50
through a pipe 203 in the atmosphere. The classified material may be
transported from the classifying unit 40 to the screening unit 50 by the
airflow when being classified or may be transported from the classifying
unit 40 that is present in an upper portion to the screening unit 50 that
is present in a lower portion by gravity. Moreover, a suction unit for
efficiently suctioning a short fiber mixture from the upper air outlet
40c and the like may be provided in the upper air outlet 40c of the
classifying unit 40, the pipe 206, and the like. Classification is not
intended to accurately divide the defibrated material by a certain size
and density as a boundary. Furthermore, classification is not intended to
accurately divide the defibrated material into the fiber and the ink
particles. The relatively short fiber in the fibers is discharged from
the upper air outlet 40c together with the ink particles. The relatively
large fiber in the ink particles is discharged from the lower outlet 40b
together with the fiber.

[0048] The screening unit 50 screens the classified material (defibrated
material) containing the fibers that is classified by the classifying
unit 40 by passing through a sieve unit 51 having a plurality of
openings. Specifically, the classified material containing the fibers
that is classified by the classifying unit 40 is sorted into a passed
material that passes through the opening of the sieve unit 51 and a
remaining material that does not pass through the opening of the sieve
unit 51. The screening unit 50 of the embodiment includes a mechanism of
dispersing the classified material in the air by a rotating motion. Then,
the material passing through the opening by screening of the screening
unit 50 is transported from a passed material transport unit 350 on the
accumulation unit 70 side through a pipe 204. On the other hand, the
remaining material that does not pass through the opening by screening of
the screening unit 50 is returned again to the defibrating unit 30
through a pipe 205 as the material to be defibrated. Thus, the remaining
material is re-used (recycled) without being discarded.

[0049] The material passing through the opening by screening of the
screening unit 50 is transported to the accumulation unit 70 through the
pipe 204 in the atmosphere. The passed material is transported from the
screening unit 50 to the accumulation unit 70 by airflow generated by the
blower 190. Moreover, the blower 190 is omitted and the passed material
may be transported from the screening unit 50 that is present in the
upper portion to the accumulation unit 70 that is present the lower
portion by gravity. The additive feeding unit 60 for adding additives
such as binding resin (for example, thermoplastic resin or thermosetting
resin) and the like to the transported passed material is provided in the
pipe 204 between the screening unit 50 and the accumulation unit 70.
Moreover, as the additives, for example, flame retardant, whiteness
enhancer, a sheet strength enhancing agent, a sizing agent, an absorption
modifier, fragrance, deodorant, and the like may also be fed in addition
to the binding resin. The additives are stored in an additive reservoir
61 and are fed from a feeding port 62 by a feeding mechanism (not
illustrated).

[0050] The blower 190 is disposed between the additive feeding unit 60 and
the accumulation unit 70. Both ends of the blower 190 are connected to
the pipes 204 and the blower 190 is provided to generate the airflow from
the additive feeding unit 60 side to the accumulation unit 70 side.
Furthermore, the blower 190 includes a rotation unit (for example, fan
blades) and the fiber and additives introduced into the blower 190 are
mixed by rotating the rotation unit. Then, a mixture (material containing
the fiber) in which the fiber and the additives are mixed is discharged
on the accumulation unit 70 side by the airflow.

[0051] The accumulation unit 70 is provided to accumulate at least a part
of the defibrated material that is defibrated by the defibrating unit 30
in the atmosphere. Specifically, the accumulation unit 70 has a function
of uniformly dispersing the fiber in the atmosphere and a function of
accumulating the dispersed fiber on a mesh belt 73. The accumulation unit
70 accumulates the material (mixture) containing the fiber and the
binding resin fed from the pipe 204 on the mesh belt 73 and forms a web
W. Moreover, the web W according to the embodiment refers to a
configuration form of an object containing the fiber and the binding
resin. Thus, the web W is illustrated as a web W even if the form such as
dimensions is changed when heating, pressing, cutting, transporting the
web, and the like.

[0052] As a mechanism of uniformly dispersing the fiber in the atmosphere,
a drum unit 300 into which the fiber and the binding resin are fed is
disposed in the accumulation unit 70. Then, it is possible to uniformly
mix the binding resin (additive) in the passed material (fiber) by
driving the drum unit 300 to rotate. A screen (opening section) having a
plurality of small holes (openings) is provided in the drum unit 300.
Then, it is possible to uniformly mix the binding resin (additives) in
the passed material (fiber) by driving the drum unit 300 to rotate. Then,
binding resin (additive) in the passed material (fiber) is uniformly
mixed and it is possible to uniformly disperse the fibers or the mixture
of the fibers and binding resin passing through the small holes in the
atmosphere by driving the drum unit 300 to rotate.

[0053] An endless mesh belt 73 in which a mesh is formed is disposed below
the drum unit 300. The mesh belt 73 is stretched by stretching rollers 72
and the mesh belt 73 is moved in one direction by rotating at least one
of the stretching rollers 72.

[0054] Furthermore, a suction device 75 as a suction unit for suctioning
the air within a housing unit 400 surrounding the drum unit 300 through
the mesh belt 73 is provided vertically below the drum unit 300. The
airflow is generated by the suction device 75 from an upper side to a
lower side (from the drum unit 300 to the mesh belt 73) and it is
possible to suck the fiber (mixture) dispersed in the atmosphere on the
mesh belt 73.

[0055] Then, the fiber and the like passing through the small hole screen
of the drum unit 300 are accumulated on the mesh belt 73 by assisting of
a suction force by the suction device 75. In this case, it is possible to
form an accumulated material (web W) of an elongated shape containing the
fiber and the binding resin by moving the mesh belt 73 in one direction.
The continuous strip-shaped continuous web W is formed by continuously
performing dispersion from the drum unit 300 and moving of the mesh belt
73. Moreover, the mesh belt 73 may be made of metal, resin, and nonwoven
fabric, and may be any one as long as the fiber can be accumulated and
the airflow can be passed through. Moreover, if a hole diameter of the
mesh of the mesh belt 73 is too large, the fiber enters between the
meshes and becomes uneven when forming the web W (sheet), on the other
hand, if the hole diameter of the mesh is too small, a stable airflow by
the suction device 75 is difficult to form. Thus, it is preferable that
the hole diameter of the mesh is appropriately adjusted (set). The
suction device 75 can be configured by disposing a closed box (box)
having a window of a desired size opened under the mesh belt 73,
suctioning air from the outside of the window, and making the inside of
the box be a negative pressure.

[0056] The web W formed on the mesh belt 73 is transported in a transport
direction (white arrows in the view) by rotation of the mesh belt 73. An
intermediate transport unit 90 is disposed on an upper side of the mesh
belt 73 as a release unit. The web W is released from the mesh belt 73 by
the intermediate transport unit 90 and is transported on the forming unit
100 side. The intermediate transport unit 90 is configured so as to
transport the web W while suctioning the web W vertically upward
(direction separating the web W from the mesh belt 73). The intermediate
transport unit 90 is disposed by being separated from the mesh belt 73
vertically upward (direction perpendicular to a surface of the web W) and
a part of the intermediate transport unit 90 is disposed to be shifted to
the mesh belt 73 on a downstream side in the transport direction of the
web W. Then, a transporting section of the intermediate transport unit 90
is a section from a stretching roller 72a on the downstream side of the
mesh belt 73 to a pressing unit 110 that is a part of the forming unit
100.

[0057] The intermediate transport unit 90 has a transport belt 91, a
plurality of stretching rollers 92, and a suction chamber 93. The
transport belt 91 is an endless mesh belt in which the mesh is formed and
which is stretched by the stretching rollers 92. Then, the transport belt
91 is rotated (moves) in one direction by rotating at least one of the
plurality of stretching rollers 92.

[0058] The suction chamber 93 is disposed on an inside of the transport
belt 91 and has a hollow box shape having an upper surface and four side
surfaces coming into contact with the upper surface, and of which a
bottom surface (surface facing the transport belt 91 positioned below) is
opened. Furthermore, the suction chamber 93 includes a suction unit
generating the airflow (suction force) into the suction chamber 93. Then,
an inner space of the suction chamber 93 is suctioned and air flows from
the bottom surface of the suction chamber 93 by driving the suction unit.
Thus, the airflow is generated upward on the inside of the suction
chamber 93, the web W is suctioned from above, and the web W can be
suctioned to the transport belt 91. Then, the transport belt 91 is moved
(circulated) by rotating the stretching rollers 92 and can transport the
web W to the pressing unit 110. Furthermore, the suction chamber 93
overlaps a part of the mesh belt 73 when viewed from above and is
disposed in a position on the downstream side where the suction device 75
does not overlap. Thus, the web W on the mesh belt 73 is released from
the mesh belt 73 in a position facing the suction chamber 93 and can be
suctioned to the transport belt 91. The stretching rollers 92 rotate such
that the transport belt 91 moves at the same speed as that of the mesh
belt 73. If there is a difference in the speeds of the mesh belt 73 and
the transport belt 91, it is possible to prevent that the web W is broken
or buckled by being pulled by making the speed thereof be the same speed.

[0059] The forming unit 100 is provided to form a sheet Pr by using the
accumulated material. The forming unit 100 of the embodiment includes the
pressing unit 110, a heating unit 120, a cutting unit 130, and the like.
The pressing unit 110 is provided to press the web W as the accumulated
material that is accumulated by the accumulation unit 70. The pressing
unit 110 is configured of a pair of pressing rollers 111 and 112, and
initially presses the web W. That is, the sheet manufacturing apparatus 1
has a configuration which does not have another pressing unit (for
example, another pair of pressing rollers) for pressing the web W formed
between the accumulation unit 70 and the pressing unit 110 by the
accumulation unit 70. Moreover, the pressing unit 110 of the embodiment
presses the web W so as to be approximately 1/5 to 1/30 of the thickness
of the web W formed by the accumulation unit 70. Thus, a configuration,
in which a single roller, the transfer belt, and the like are disposed
between the accumulation unit 70 and the pressing unit 110 for simply
transporting the web W, may be provided. Furthermore, a configuration, in
which rollers (pair of rollers) finely pressing (pressure of an extent
not beyond a pressure to be the above described thickness of the web W)
the web W is disposed, may be provided. Then, the pressing unit 110
presses the web W transported by the intermediate transport unit 90 by
interposing the web W between the pair of pressing rollers 111 and 112.
Thus, it is possible to enhance the strength of the web W by pressing the
web W. Moreover, a detailed configuration of the pressing unit 110 will
be described below.

[0060] The heating unit 120 is disposed on a downstream side of the
pressing unit 110 in the transport direction. The heating unit 120 is
provided to bind the fibers containing the web W through the binding
resin. The heating unit 120 of the embodiment is configured of a pair of
heating rollers 121 and 122. A heating member (heating source) such as a
heater is provided in a center portion of rotary shafts of the heating
rollers 121 and 122, and it is possible to heat and press the web W by
transporting the web W by pinching the web W by the pair of heating
rollers 121 and 122. The web W is heated and pressed and thereby the
binding resin is easily entangled with the fiber by being melted, fiber
intervals between the fibers are shortened, and contact points between
the fibers are increased. Thus, the strength is enhanced as the web W
having high density.

[0061] As the cutting unit 130 cutting the web W, a first cutting unit
130a cutting the web W in a direction intersecting the transport
direction of the web W and a second cutting unit 130b cutting the web W
along the transport direction of the web W are disposed on the downstream
side of the heating unit 120 in the transport direction. The first
cutting unit 130a includes a cutter and cuts the continuous web W in a
sheet form according to a cutting position that is set in a predetermined
length. The second cutting unit 130b has a cutter and cuts the web W
according to a predetermined cutting position in the transport direction
of the web W. Thus, the sheet Pr (web W) of a desired size is formed. The
cut sheets Pr are stacked on a stacker 160 and the like. Moreover, it may
be configured so as to wind the continuous web W by a winding roller in a
roll shape by a winding roller without cutting the web W. As described
above, it is possible to manufacture the sheet Pr in the sheet
manufacturing apparatus 1.

[0062] Moreover, the sheet according to the embodiment mainly refers to
that formed in a sheet shape, which contains the fiber such as the used
paper and the pure pulp as the raw material. However, the sheet is not
limited to the embodiment and may be a board shape or a web shape (or a
shape having unevenness). Furthermore, as the raw material, plant fibers
such as cellulose, chemical fibers such as polyethylene terephthalate
(PET) and polyester, and animal fibers such as wool and silk may be
included. The sheet in the present application is divided into paper and
non-woven fabric. Paper includes aspects formed in a thin sheet shape and
includes recording paper for writing or printing, wallpaper, wrapping
paper, colored paper, Kent paper, and the like. Non-woven fabric has a
thickness thicker than that of paper or has a strength lower than that of
paper, and includes non-woven fabric, fiber board, tissue paper, kitchen
paper, cleaner, filter, liquid absorption material, sound-absorbing
material, cushioning material, mat, and the like.

[0063] Furthermore, the used paper in the embodiment described above
mainly refers to printed paper and it is regarded as the used paper
regardless of whether or not the paper is used as long as paper is formed
as the raw material.

[0064] Next, a detailed configuration of the accumulation unit 70 will be
described. FIGS. 2A and 2B are schematic views illustrating the
configuration of the accumulation unit, FIG. 2A is a sectional view in a
rotation axis direction, and FIG. 2B is a sectional view that is taken
along line IIB-IIB in FIG. 2A. Furthermore, FIG. 3 is a perspective view
illustrating a configuration of the drum unit.

[0065] As illustrated in FIGS. 2A and 2B, the accumulation unit 70
includes the drum unit 300, a material supply unit 500, the housing unit
400, and the like. Furthermore, the accumulation unit 70 includes a
diffusion section 700, which diffuses the airflow from an upstream side
to a downstream side in a supply direction of the airflow flowing through
the drum unit, in at least one of the drum unit 300 and the material
supply unit 500. Here, "diffusing" means to have a component in a
direction (direction toward a peripheral surface) perpendicular to an
extending direction of a rotation axis R of the drum unit 300 that is an
airflow direction of a material supply port 560 in FIG. 2A. Hereinafter,
specific description will be given.

[0066] The drum unit 300 has a rotatable cylindrical section 305 and as
illustrated in FIG. 3, the cylindrical section 305 has an opening section
310 having a plurality of openings 311 and a tubular unit 315 having no
opening 311. The opening section 310 and the tubular unit 315 are
coupled, for example, by welding or screws, and are integrally rotated.
The cylindrical section 305 is formed in a cylindrical shape by using a
metal plate such as stainless steel having a uniform thickness and
opening ports 306 are provided on both ends thereof.

[0067] The opening section 310 is configured of a punched metal in which
the plurality of openings 311 are provided. The opening section 310 is
configured such that the material containing the fibers passes through
the openings 311 and is dispersed. A size, a forming region of the
openings 311, and the like are appropriately set by a size and a type of
the material, and the like. Moreover, the opening section 310 is not
limited to the punched metal and may be a wire mesh material and the
like. The plurality of openings 311 are disposed in the same size (area)
respectively at equal intervals. Thus, the material passing through the
openings 311 is accumulated on the mesh belt 73 with uniform thickness
and density. Furthermore, when passing through the openings 311, the
entangled fibers are loosened. The tubular unit 315 is a portion which
does not have the opening 311 and the like and is a portion coming into
contact with the housing unit 400.

[0068] The housing unit 400 surrounds a periphery of the drum unit 300 and
as illustrated in FIGS. 2A and 2B, has a frame 401 of which five wall
surfaces are bonded, and has a space unit on an inside thereof. A lower
portion of the housing unit 400 is not a wall surface and an opening 406
is provided. Furthermore, the housing unit 400 has frame bonding surfaces
401a that are circular openings on two wall surfaces facing in the
rotation axis direction R of the drum unit 300 and first pile seal units
410 described below are bonded to the frame bonding surfaces 401a. The
housing unit 400 does not have openings other than the opening 406 and
the frame bonding surface 401a. The housing unit 400 surrounds the drum
unit 300 such that the opening section 310 of the drum unit 300 is
disposed on an inside thereof. That is, the opening section 310 of the
drum unit 300 is positioned within a space on the inside of the housing
unit 400. Then, the housing unit 400 and the tubular unit 315 come into
contact with each other through the first pile seal units 410. In the
embodiment, as illustrated in FIG. 3, the drum unit 300 has a tubular
unit 315a, the opening section 310, and a tubular unit 315b in the
extending direction of a rotation axis R, and as illustrated in FIGS. 2A
and 2B, the housing unit 400 comes into contact with a surface S1 of the
cylindrical section in the tubular units 315a and 315b. As described
above, the housing unit 400 comes into contact with the tubular units
315a and 315b and thereby it is possible to suppress discharge of the
material containing the fibers and the like passing through the openings
311 from the inside of the housing unit 400 to the outside of the housing
unit 400. Furthermore, the housing unit 400 is disposed on the inside of
the drum unit 300 in the rotation axis direction R of the drum unit 300.
Thus, a width dimension of the housing unit 400 may be shorter than a
width dimension of the drum unit 300 in the rotation axis direction R and
it is possible to reduce a size of the apparatus. Moreover, a dimension
of the housing unit 400 is greater than an outer diameter dimension of
the drum unit 300 in a direction orthogonal to the rotation axis
direction R of the drum unit 300 and thereby the drum unit 300 is
disposed on an inside of the housing unit 400.

[0069] Furthermore, the housing unit 400 of the embodiment has the first
pile seal unit 410 and the surface S1 of the tubular unit 315 comes into
contact with the first pile seal unit 410 (sliding contact). The first
pile seal unit 410 is configured of, for example, a base unit and a
plurality of fibers that are densely planted on one surface side of the
base unit. The first pile seal unit 410 has the plurality of fibers (pile
yarns) which are densely planted to the extent that the fibers passing
through the openings 311 of the drum unit 300 cannot pass through the
plurality of fibers. Then, it is configured such that the other surface
of the base unit of the first pile seal unit 410 is bonded to the frame
bonding surface 401a of the housing unit 400 and tip end portions of the
fibers of the first pile seal unit 410 come into contact with the surface
S1 of the tubular unit 315. The openings 311 are not formed on the
surface S1 of the tubular unit 315 coming into contact with the first
pile seal unit 410. Furthermore, it is preferable that unevenness is not
present at least on the surface S1 coming into contact with the first
pile seal unit 410. Thus, a gap between the frame 401 of the housing unit
400 and the tubular unit 315 of the drum unit 300 is substantially closed
by the first pile seal unit 410. Thus, the material containing the fibers
and the like passing through the openings 311 of the drum unit 300 are
held on the inside of the housing unit 400 and it is possible to suppress
discharge of the material to the outside of the housing unit 400.
Furthermore, it is possible to suppress entry of foreign materials from
the outside of the housing unit 400. Furthermore, when the drum unit 300
is rotated about the rotation axis direction R, wear in a sliding portion
between the tubular unit 315 and the first pile seal unit 410 is
suppressed and it is possible to reduce a rotational load of the drum
unit 300. Moreover, the length of the fiber of the first pile seal unit
410 is set to be longer than the gap between the frame 401 of the housing
unit 400 and the tubular unit 315 of the drum unit 300. It is because the
first pile seal unit 410 reliably comes into contact with the tubular
unit 315. Moreover, the first pile seal unit 410 may be provided in the
tubular unit 315. However, in this case, the drum unit 300 is shifted to
the housing unit 400 in an extending direction of the rotation axis
direction R, and there is a concern that a contact area between the first
pile seal unit 410 and the frame 401 is reduced. Thus, it is preferable
that the first pile seal unit 410 is provided in the housing unit 400 and
comes into contact with the tubular unit 315 with a size greater than
(width is wider) the first pile seal unit 410 in the extending direction
of the rotation axis direction R.

[0070] Furthermore, in the embodiment, as illustrated in FIGS. 2A and 2B,
the fixed material supply units 500 are provided on the inside of the
tubular unit 315 of the drum unit 300. In the embodiment, the pipes 204
are divided into two parts and are respectively connected to the material
supply units 500 corresponding to the tubular unit 315 of both ends of
the drum unit 300. The material supply units 500 are provided to supply
the material containing the fibers passing through the pipe 204 to the
drum unit 300. The material supply unit 500 of the embodiment configures
the diffusion section 700 of which a cross-sectional area on the
downstream side is greater than a cross-sectional area on the upstream
side in the flowing direction of the airflow. That is, a taper is
provided in a supply path for supplying the material containing the
fibers from the pipe 204 to the inside of the drum unit 300. The supply
path is gradually widened from the pipe 204 side to the drum unit 300
(opening section 310) side. Furthermore, as illustrated in FIG. 2A, an
end portion of the material supply unit 500 on the downstream side is
applied to the opening section 310 in sectional view. Moreover, a length
and a taper amount of the material supply unit 500 from an end portion on
the upstream side to the end portion on the downstream side are
appropriately set in compliance with the intensity of the airflow and the
like.

[0071] The material supply unit 500 comes into contact with the tubular
unit 315 through a second pile seal unit 420. That is, the material
supply unit 500 and the tubular unit 315 are configured to be slidable
through the second pile seal unit 420. In the embodiment, the material
supply unit 500 is disposed on insides of both tubular units 315a and
315b of the drum unit 300. The end portion of the material supply unit
500 on the upstream side is fixed to a flange fixing plate 550. Then, the
flange fixing plate 550 is fixed to an external frame (not illustrated).
The material supply port 560 for supplying the material containing the
fibers to the inside of the drum unit 300 is provided in the flange
fixing plate 550.

[0072] The second pile seal unit 420 is provided between a rear surface S2
of the tubular unit 315 and a surface 502 of the material supply unit
500. The second pile seal unit 420 is configured of, for example, a base
unit and a plurality of fibers that are densely planted on one surface
side of the base unit. The second pile seal unit 420 has the plurality of
fibers which are densely planted to an extent that the material
containing the fibers cannot pass through the plurality of fibers. Then,
in the embodiment, it is configured such that the other surface of the
base unit of the second pile seal unit 420 is bonded to the surface 502
of the material supply unit 500 and tip end portions of the fibers of the
second pile seal unit 420 come into contact with the rear surface S2 of
the tubular unit 315. Thus, a gap between the material supply unit 500
and the tubular unit 315 of the drum unit 300 is substantially closed by
the second pile seal unit 420. Thus, it is possible to suppress discharge
of the material containing the fibers to the outside from the gap between
the tubular unit 315 and the material supply unit 500. Furthermore, it is
possible to suppress entry of foreign materials from the outside of the
material supply unit 500. Furthermore, since the drum unit 300 is rotated
about the rotation axis R, wear in a sliding portion, where the tubular
unit 315 and the second pile seal unit 420 are rubbed, is suppressed and
it is possible to reduce the rotational load of the drum unit 300.
Moreover, the length of the fiber of the second pile seal unit 420 is,
for example, set to be longer than the gap between the material supply
unit 500 and the tubular unit 315 of the drum unit 300. It is because the
second pile seal unit 420 reliably comes into contact with the tubular
unit 315. Since the second pile seal unit 420 is bonded to the material
supply unit 500, the material supply unit 500 can be said to have the
second pile seal unit 420. Moreover, the second pile seal unit 420 may be
bonded to the tubular unit 315.

[0073] Furthermore, the second pile seal unit 420 is bonded to the
lowermost downstream side (opening section 310 side) in the material
supply unit 500. The second pile seal unit 420 is not limited to the
configuration and may be provided in a position on a further upstream
side (material supply port 560 side) than a position illustrated in FIG.
2A. In this case, a gap is generated between the material supply unit 500
and the tubular unit 315, the material containing the fibers enters the
gap, and then a sliding load of the drum unit 300 may be increased. Thus,
if the second pile seal unit 420 is bonded to the end portion of the
material supply unit 500 on the downstream side (opening section 310
side), it is preferable in that the increase in the sliding load can be
prevented. Moreover, the drum unit 300 is supported by a support unit
(not illustrated) and weight of the drum unit 300 is not applied to the
first pile seal unit 410 or the second pile seal unit 420.

[0074] Furthermore, in the embodiment, as illustrated in FIG. 2B, the
housing unit 400 has a roller 450 coming into contact with the web W on
the downstream side in the transport direction of the web W. Furthermore,
the housing unit 400 has a third pile seal unit 430 coming into contact
with the mesh belt 73 on the further upstream side in the transport
direction of the web W than a position where the roller 450 is disposed.

[0075] The third pile seal unit 430 is configured of, for example, a base
unit and a plurality of fibers that are densely planted on one surface
side of the base unit. The third pile seal unit 430 has the plurality of
fibers (pile yarns) which are densely planted to the extent that the
material containing the fibers passing through the drum unit 300 cannot
pass through the plurality of fibers. Then, the third pile seal units 430
are disposed in a position other than the position in which the roller
450 of the housing unit 400 is disposed. That is, the third pile seal
units 430 are disposed in three positions of the frame 401 of the housing
unit 400. It is configured such that the other surface of the base unit
of the third pile seal unit 430 is bonded to a frame bonding surface 402a
of the housing unit 400 and tip end portions of the fibers of the third
pile seal unit 430 come into contact with a surface S3 of the mesh belt
73. A dimension (width) of the mesh belt 73 is greater than that of and
the housing unit 400 in a direction orthogonal to a moving direction (the
transport direction of the web W) of the mesh belt 73. Thus, the gap
between three sides of the housing unit 400 and the mesh belt 73 is
configured to be substantially closed by the third pile seal unit 430.
When the mesh belt 73 is moved (rotated), wear of the mesh belt 73 and
the third pile seal unit 430 is suppressed and it is possible to reduce
the load to the mesh belt 73. A length of the third pile seal unit 430 is
set, for example, to be longer than the gap between the frame bonding
surface 402a of the frame 401 of the housing unit 400 and the mesh belt
73. The third pile seal unit 430 reliably comes into contact with the
mesh belt 73.

[0076] As illustrated in FIG. 2B, the roller 450 of the housing unit 400
has a rotation axis along a direction (width direction of the web W)
intersecting the transport direction of the web W. Furthermore, the
roller 450 has a length equal to the width dimension (width direction of
the web W) of the frame 401 in the width direction of the web W.

[0077] Furthermore, the roller 450 is connected to a driving unit (not
illustrated) such as a motor driving the roller 450. The web W is easily
pulled in the transport direction and it is possible to reliably
transport the web W by driving the roller 450 to be rotated
(counterclockwise direction in FIG. 2B). Furthermore, the roller 450 is
capable of moving in an up and down direction (direction intersecting an
accumulation surface of the mesh belt 73 or the thickness direction of
the web W) and is biased downward (mesh belt 73 side) by a biasing member
(not illustrated). Thus, a position according to the thickness of the web
W accumulated on the mesh belt 73 is variable by the drum unit 300 and it
is possible to transport the web W without destroying it even if the web
W having a different thickness is transported.

[0078] Furthermore, on the downstream side in the transport direction of
the web W, the housing unit 400 has a fourth pile seal unit 440 and the
fourth pile seal unit 440 comes into contact with the roller 450. Since a
configuration of the fourth pile seal unit 440 is the same as that of the
third pile seal unit 430, the description will be omitted. Then, it is
configured such that the other surface of the base unit of the fourth
pile seal unit 440 is bonded to the frame of the housing unit 400 and tip
end portions of the fibers of the fourth pile seal unit 440 come into
contact with a surface (peripheral surface) of the roller 450. Thus, a
gap between the frame bonding surface 402a of the housing unit 400 and
the roller 450 is substantially closed by the fourth pile seal unit 440.
Furthermore, generation of wear in a sliding portion, where the roller
450 that is driven to rotate and the fourth pile seal unit 440 are
rubbed, is suppressed and it is possible to reduce a load to the roller
450. The length of the fiber of the fourth pile seal unit 440 is set such
that the fourth pile seal unit 440 reliably comes into contact with the
roller 450. For example, the length of the fiber of the fourth pile seal
unit 440 is set to be longer than the gap between the frame of the frame
401 of the housing unit 400 and the surface of the roller 450.

[0079] Above, as illustrated in FIGS. 2A and 2B, the gap between the
housing unit 400 and the mesh belt 73 is substantially closed by the
third pile seal unit 430 in the three positions of four positions of the
frame 401 of the housing unit 400 corresponding to the surface S3 of the
mesh belt 73. Furthermore, the gap between the housing unit 400 and the
mesh belt 73 is substantially closed by the fourth pile seal unit 440 and
the roller 450 in a remaining one position. Thus, the material containing
the fibers and the like passing (before accumulated) through the openings
311 of the drum unit 300 are held on the inside of the housing unit 400,
and it is possible to suppress discharge to the outside of the housing
unit 400.

[0080] Furthermore, in the embodiment, it is configured such that outside
air (air) is suctioned from the sliding contact part between the drum
unit 300 and the housing unit 400 when suctioning the material containing
the fibers by the suction device 75. Specifically, it is configured such
that outside air is suctioned toward the drum unit 300 and the housing
unit 400 through the first pile seal unit 410 that is the sliding contact
part between the drum unit 300 and the housing unit 400, and the second
pile seal unit 420 that is the sliding contact part between the drum unit
300 and the material supply unit 500. In this case, it is configured such
that an air flow of air suctioned by the suction device 75 is larger than
an air flow flowing from the material supply units 500 disposed in both
ends of the drum unit 300 into the drum unit 300. Thus, air is suctioned
from the outside into the housing unit 400 through the first pile seal
unit 410 and the second pile seal unit 420. Moreover, if air is suctioned
from the outside into the housing unit 400 through the third pile seal
unit 430 and the fourth pile seal unit 440, turbulence occurs in the
vicinity of the mesh belt 73 and the fibers passing through the openings
311 of the drum unit 300 are unlikely to be accumulated on the mesh belt
73. Thus, in the embodiment, densities of the third pile seal unit 430
and the fourth pile seal unit 440 are higher (densely) than densities of
the first pile seal unit 410 and the second pile seal unit 420. In this
case, for example, densities of the fibers configuring the third pile
seal unit 430 and the fourth pile seal unit 440 are higher than densities
of the fibers configuring the first pile seal unit 410 and the second
pile seal unit 420. Furthermore, the width dimensions and height
dimensions of the third pile seal unit 430 and the fourth pile seal unit
440 are greater than the width dimensions and height dimensions of the
first pile seal unit 410 and the second pile seal unit 420. Thus, it is
possible to reduce suction of outside air from the third pile seal unit
430 and the fourth pile seal unit 440.

[0081] Next, a method for operating the accumulation unit 70 will be
described. First, the fibers classified by the classifying unit 40 and
the material containing the fibers fed from the additive feeding unit 60
are supplied from the material supply unit 500 to the drum unit 300 side
through the pipe 204. The end portion of the material supply unit 500 on
the drum unit 300 side is adjacent to the opening section 310 and the
material supplied from the material supply unit 500 flows toward the
opening section 310.

[0082] Then, the drum unit 300 is driven by a driving unit (motor and the
like) (not illustrated) to be rotated about the rotation axis R. Thus,
the fibers and resin supplied on the inside of the drum unit 300 are
mixed and the material containing the fibers and resin are dispersed by a
centrifugal force. Then, the dispersed material passes through the
openings 311 of the opening section 310. The material passing through the
openings 311 falls and is accumulated on the mesh belt 73.

[0083] Here, as described above, the material supply unit 500 includes the
diffusion section 700 of which the cross-sectional area is gradually
increased from the upstream side to the downstream side. Thus, the
airflow flowing from the pipe 204 to the material supply unit 500 flows
while diffusing in the material supply unit 500 (diffusion section 700).
Then, the diffused airflow flows from the material supply unit 500 into
the drum unit 300. Thus, the material supplied from the material supply
unit 500 to the drum unit 300 (opening section 310) is efficiently
dispersed within the drum unit 300 (opening section 310) by the diffused
airflow.

[0084] Furthermore, since it is configured such that the air flow of air
suctioned by the suction device 75 is larger than the air flow flowing
from the material supply units 500 disposed in both ends of the drum unit
300 into the drum unit 300, outside air (air) is suctioned from the
outside to the inside of the housing unit 400 through the first pile seal
unit 410 and the second pile seal unit 420. A speed of the airflow in the
vicinity of the first pile seal unit 410 and the second pile seal unit
420 in the drum unit 300 is increased by the suctioned outside air. Thus,
it is possible to suppress catching or aggregation of the fibers within
the drum unit 300 or the housing unit 400.

[0085] According to the first embodiment described above, it is possible
to obtain the following effects.

[0086] The diffusion section 700 of which the cross-sectional area is
gradually increased toward the downstream side is provided in the
material supply unit 500 and thereby the material containing the fibers
is dispersed within the drum unit 300 when supplying the material to the
drum unit 300 by the airflow. Thus, fiber lumps, aggregation of the
fibers, and the like are reduced within the drum unit 300 and it is
possible to reduce the amount of the material containing the fibers that
does not pass through the openings 311 of the drum unit 300.

[0087] Furthermore, air is suctioned from the outside to the inside of the
housing unit 400 through the first pile seal unit 410 and the second pile
seal unit 420, and the speed of the airflow in the vicinity of the first
pile seal unit 410 and the second pile seal unit 420 is increased. Thus,
it is possible to suppress catching or aggregation of the fibers within
the drum unit 300 or the housing unit 400 and thus texture of the sheet
is improved.

Second Embodiment

[0088] Next, a second embodiment will be described. Since a basic
configuration of a sheet manufacturing apparatus is the same as that of
the first embodiment, description thereof will be omitted. Hereinafter, a
configuration different from the first embodiment, that is, a
configuration of an accumulation unit is mainly described.

[0089] FIG. 4 is a schematic view illustrating the configuration of the
accumulation unit according to the embodiment. As illustrated in FIG. 4,
an accumulation unit 70a includes a drum unit 300, a material supply unit
500a, a housing unit 400, and the like. Same reference numerals are given
to members having the same functions as the configuration members of the
first embodiment and detailed description will be omitted.

[0090] In the embodiment, the fixed material supply unit 500a is provided
on insides of tubular units 315a and 315b of the drum unit 300. Similar
to the first embodiment, pipes 204 divided into two parts are
respectively connected to the material supply units 500a. The material
supply units 500a are provided to supply the material containing the
fibers passing through the pipes 204 to the drum unit 300. An inner
diameter (flow diameter) of the material supply unit 500a is uniform.
That is, a cross-sectional area from the upstream side to the downstream
side is equal to each other in the material supply unit 500a. An end
portion of the material supply unit 500a on the downstream side is
adjacent to an opening section 310 in sectional view. A length, a flow
path diameter from an end portion on the upstream side to an end portion
on the downstream side of the material supply unit 500a, and the like are
appropriately set in compliance with intensity of the airflow and the
like.

[0091] The accumulation unit 70a includes a diffusion section 700a in at
least one of the drum unit 300 and the material supply unit 500a. The
diffusion section 700a is provided such that the airflow is diffused on
the downstream side more than the upstream side in a supply direction
(flowing direction) of the airflow. The diffusion section 700a of the
embodiment is a changing section 510 that changes a direction of the
airflow within the drum unit 300.

[0092] As illustrated in FIG. 4, the changing sections 510 are positioned
in a region in which the opening section 310 is disposed in sectional
view, are positioned in positions separated from the material supply
units 500a, and are disposed such that at least a part of the changing
section 510 faces the material supply port 560. The changing section 510
is supplied on the material supply unit 500a by a support unit (not
illustrated). The changing section 510 of the embodiment is a plate
member and is disposed such that a facing surface 510a facing the
material supply port 560 is substantially perpendicular to a rotation
axis R of the drum unit 300. That is, the facing surface 510a is formed
in a direction that is substantially perpendicular to the flowing
direction of the airflow in the material supply unit 500a.

[0093] Furthermore, the housing unit 400 has a roller 450 coming into
contact with a web W and a fourth pile seal unit 440 in the downstream
side in the transport direction of the web W (see FIG. 2B). Furthermore,
similar to the first embodiment, it is configured such that outside air
is suctioned from a sliding contact part (first pile seal unit 410 and a
second pile seal unit 420) between the drum unit 300 and the housing unit
400 when suctioning the material containing the fibers by the suction
device 75.

[0094] The airflow flowing from the material supply port 560 of the
material supply unit 500a into the drum unit 300 collides with the
changing section 510, is diffused, and flows on an upper side and a lower
side of the drum unit 300. Thus, the material supplied from the material
supply unit 500a to the drum unit 300 (opening section 310) is
efficiently dispersed within the drum unit 300 (opening section 310) by
the diffused airflow.

[0095] Furthermore, similar to the first embodiment, the speed of the
airflow in the vicinity of the first pile seal unit 410 and the second
pile seal unit 420 is increased by outside air suctioned from the first
pile seal unit 410 and the second pile seal unit 420. Thus, it is
possible to suppress catching and aggregation of the fibers within the
drum unit 300 or the housing unit 400.

[0096] According to the second embodiment described above, it is possible
to obtain the following effects.

[0097] The airflow flowing from the material supply unit 500a into the
drum unit 300 collides with the changing section 510 and the direction of
the airflow is changed on the upper side and the lower side of the drum
unit 300, and the airflow is diffused. Thus, a dispersing effect of the
material is enhanced, fiber lumps, aggregation of the fibers, and the
like are reduced within the drum unit 300, and it is possible to reduce
the amount of the material containing the fibers that does not pass
through the openings 311 of the drum unit 300.

Third Embodiment

[0098] Next, a third embodiment will be described. Since a basic
configuration of a sheet manufacturing apparatus is the same as that of
the first embodiment, description thereof will be omitted. Hereinafter, a
configuration different from the first embodiment, that is, a
configuration of an accumulation unit is mainly described.

[0099] FIG. 5 is a schematic view illustrating the configuration of the
accumulation unit according to the embodiment. As illustrated in FIG. 5,
an accumulation unit 70b includes a drum unit 300, a material supply unit
500b, a housing unit 400, and the like. Same reference numerals are given
to members having the same functions as the configuration members of the
first embodiment and detailed description will be omitted.

[0100] In the embodiment, the fixed material supply unit 500b is provided
on an outside of the tubular unit 315 of the drum unit 300 and the
tubular unit 315 comes into contact with the material supply unit 500b
through a second pile seal unit 420. That is, the material supply unit
500b and the second pile seal unit 420 are disposed on the outside of
both tubular units 315a and 315b of the drum unit 300. A material supply
port 560a for supplying the material containing the fibers to an inside
of the drum unit 300 is provided in the material supply unit 500b. The
material supply ports 560a are respectively connected to pipes 204 that
are divided into two parts. The material supply unit 500b is provided to
supply the material containing the fibers passing through the pipe 204 to
the drum unit 300.

[0101] Then, a second pile seal unit 420 is provided between a surface
(outer peripheral surface) S1 of the tubular unit 315 and a rear (back)
surface (inner peripheral surface) 501a of the material supply unit 500b.
It is configured such that the other surface of a base unit of the second
pile seal unit 420 is bonded to the rear surface 501a of the material
supply unit 500b and tip end portions of the fibers of the second pile
seal unit 420 come into contact with the surface S1 of the tubular unit
315. Thus, a gap between the material supply unit 500b and the tubular
unit 315 of the drum unit 300 is substantially closed by the second pile
seal unit 420.

[0102] Then, a supply port 560a of the material supply unit 500b is
disposed in a position in which the airflow is diffused within the drum
unit 300 with respect to the opening section 310. Specifically, the
supply port 560a is provided in a position that is separated from an end
portion of the opening section 310 by a distance D in the rotation axis
direction R. That is, the supply port 560a is not disposed in a region of
the opening section 310, is not adjacent to the opening section 310, and
is disposed being separated from the end portion of the opening section
310 with a gap of the distance D. Moreover, the distance D between the
supply port 560a and the end portion of the opening section 310 is
appropriately set in compliance with intensity of the airflow.

[0103] Furthermore, the housing unit 400 has the roller 450 coming into
contact with the web W and the fourth pile seal unit 440 on the
downstream side in the transport direction of the web W (see FIG. 2B).
Furthermore, similar to the first embodiment, it is configured such that
outside air is suctioned from a sliding contact part (first pile seal
unit 410) between the drum unit 300 and the housing unit 400 when
suctioning the material containing the fibers by the suction device 75.

[0104] Here, an opening area of the opening port 306 of the drum unit 300
is wider than an opening area of the supply port 560a and the distance D
is provided from the supply port 560a to the opening section 310 in the
rotation axis direction R. Thus, the airflow flowing from the supply port
560a into the drum unit 300 is diffused and flows from the supply port
560a to the opening section 310 of the drum unit 300. Thus, the material
supplied from the material supply unit 500b to the drum unit 300 is
efficiently dispersed within the drum unit 300 by the diffused airflow.

[0105] Furthermore, similar to the first embodiment, the speed of the
airflow in the vicinity of the first pile seal unit 410 is increased by
outside air suctioned from the first pile seal unit 410. Thus, it is
possible to suppress catching and aggregation of the fibers within the
drum unit 300 or the housing unit 400.

[0106] According to the third embodiment described above, it is possible
to obtain the following effects.

[0107] The supply port 560a and the opening section 310 are disposed with
the gap by providing the distance D in the rotation axis direction R and
thereby the airflow flowing from the supply port 560a flows into the
opening section 310. Thus, a dispersing effect of the material is
enhanced, fiber lumps, aggregation of the fibers that are mass of the
fibers, and the like are reduced within the drum unit 300, and it is
possible to reduce an amount of the material containing the fibers that
does not pass through the drum unit 300.

Fourth Embodiment

[0108] Next, a fourth embodiment will be described. Since a basic
configuration of the sheet manufacturing apparatus is the same as that of
the first embodiment, description thereof will be omitted. Hereinafter, a
configuration different from the first embodiment, that is, a
configuration of an accumulation unit is mainly described.

[0109] FIG. 6 is a schematic view illustrating the configuration of the
accumulation unit according to the embodiment. As illustrated in FIG. 6,
an accumulation unit 70c includes a drum unit 300, a material supply unit
500a, a housing unit 400, and the like. Same reference numerals are given
to members having the same functions as the configuration members of the
above embodiment and detailed description will be omitted.

[0110] In the embodiment, the fixed material supply unit 500a is provided
on insides of tubular units 315a and 315b of the drum unit 300. Similar
to the first embodiment, pipes 204 divided into two parts are
respectively connected to the material supply units 500a. The material
supply units 500a are provided to supply the material containing the
fibers passing through the pipes 204 to the drum unit 300. An inner
diameter (flow diameter) of the material supply unit 500a is uniform.
That is, a cross-sectional area from the upstream side to the downstream
side is equal to each other in the material supply unit 500a. An end
portion of the material supply unit 500a on the downstream side is
adjacent to an opening section 310 in sectional view. A length, a flow
path diameter from an end portion on the upstream side to an end portion
on the downstream side of the material supply unit 500a, and the like are
appropriately set in compliance with intensity of the airflow and the
like.

[0111] Furthermore, the housing unit 400 has the roller 450 coming into
contact with the web W and the fourth pile seal unit 440 on the
downstream side in the transport direction of the web W (see FIG. 2B).
Furthermore, similar to the first embodiment, it is configured such that
outside air is suctioned from a sliding contact part (first pile seal
unit 410 and the second pile seal unit 420) between the drum unit 300 and
the housing unit 400 when suctioning the material containing the fibers
by the suction device 75. The speed of the airflow in the vicinity of the
first pile seal unit 410 and the second pile seal unit 420 is increased
by outside air suctioned from the first pile seal unit 410 and the second
pile seal unit 420. Thus, it is possible to suppress catching and
aggregation of the fibers within the drum unit 300 or the housing unit
400.

[0112] According to the fourth embodiment described above, it is possible
to obtain the following effects.

[0113] Air is suctioned from the outside to the inside of the housing unit
400 through the first pile seal unit 410 and the second pile seal unit
420. Thus, dispersion of the material containing the fibers is enhanced
within the drum unit 300. Fiber lumps, aggregation of the fibers that are
mass of the fibers, and the like are reduced within the drum unit 300 and
the housing unit 400, and thus texture of the sheet is improved.

[0114] Moreover, the invention is not limited to the embodiments described
above and it is possible to add various modifications and improvements to
the embodiments. Modification examples are described as follows.
Furthermore, each embodiment described above and each of modification
examples described below may be appropriately combined.

Modification Example 1

[0115] In the accumulation unit 70a of the second embodiment, the changing
sections 510 are disposed such that the facing surfaces 510a of the
changing sections 510 for changing the direction of the airflow are
positioned in the direction substantially perpendicular to the rotation
axis R of the drum unit 300, but the invention is not limited to
configuration. FIGS. 7A and 7B are schematic views illustrating
configurations of the accumulation unit according to Modification Example
1. As illustrated in FIG. 7A, changing sections 511 in an accumulation
unit 70d are plate members and facing surfaces 511a facing the material
supply ports 560 are disposed so as to incline with respect to the
rotation axis R of the drum unit 300. Also, in this case, the airflow
from the material supply unit 500 into the drum unit 300 collides with
the changing section 511 and a direction thereof is changed and diffused
on an upper side and a lower side of the drum unit 300. Thus, a
dispersing effect of the material is enhanced, fiber lumps, aggregation
of the fibers that are mass of the fibers, and the like are reduced
within the drum unit 300, and it is possible to reduce the amount of the
material containing the fibers that does not pass through the drum unit
300.

[0116] Furthermore, as illustrated in FIG. 7B, changing sections 512 in an
accumulation unit 70e are plate members and facing surfaces 512a facing
material supply ports 560 are bent. Also, in this case, it is possible to
obtain the same effects as the above description.

Modification Example 2

[0117] In the first to fourth embodiments described above, the first to
fourth pile seal units 410, 420, 430, and 440 are provided, but the
invention is not limited to the configurations. FIG. 8 is a schematic
view illustrating a configuration of an accumulation unit according to
Modification Example 2. As illustrated in FIG. 8, an accumulation unit
70f has a configuration in which a pile seal unit is omitted.
Specifically, a space unit 601 is provided between a drum unit 300 and a
housing unit 400, and a space unit 602 is provided between the drum unit
300 and a material supply unit 500a. Moreover, a lower end portion of the
housing unit 400 is connected to a support unit 610 supporting both ends
of a mesh belt 73. Thus, flow of air to the outside is eliminated in the
lower end portion of the housing unit 400. Then, it is configured such
that air flow of air suctioned by a suction device 75 is larger than air
flow flowing from the material supply unit 500a disposed both ends of the
drum unit 300 into the drum unit 300. Thus, outside air (air) is
suctioned from the outside to the inside of the housing unit 400 through
the space units 601 and 602. Fiber lumps, aggregation of the fibers, and
the like are reduced within the drum unit 300 and the housing unit 400,
and thus texture of the sheet is improved. Furthermore, it is possible to
simplify the configuration of the accumulation unit 70f by omitting the
pile seal unit.